The bag mag was the father of the Grafmatic, and does the same thing as a Grafmatic only a bit more awkwardly.

You load the film in each septum, like a Grafmatic, and it shoots like a Grafmatic.

The film advance is accomplished by pulling a small ring attached to a strap. This pulls the exposed septum into the leather bag, where you grab it and direct it to the back of the stack and slide it in without bending it.

The count is accompished through the red window in the back. Each septum is numbered, and as long as you loaded them in order, the count will be accurate.